Burners are utilized in many integrated systems, such as in boilers, furnaces and water heater applications. These burners are typically fed an enriched air stream containing a predetermined concentration of fuel mixed therein. Of great importance, therefore, is the ability of the system to maintain a proper air/fuel mixture during operation of the system.
Typically, a filter box includes one or more orifices to accept incoming air and fuel streams, which are mixed within the box by motion of the air through the box. The filter box may include various baffles, blades, and other structures to enhance mixing of the air and fuel. A blower is operatively connected to the filter box, and propels the air/fuel mixture from the filter box, to an integrated burner. Any blockage of the incoming air or fuel streams, or of the flue leading to the burner, will cause a change in the air/fuel mixture being fed to the burner, with a corresponding potential for the harmful buildup of CO.
Known systems oftentimes employ one or more sensors within the filter box coupled with a variable speed blower to regulate the introduction of the air/fuel mixture to the burner. While these systems operate reasonably well during normal times, they suffer under blocked-flue or blocked-air inlet conditions due to the swirling air currents created by these adverse conditions. That is, known systems arrange the air/fuel inlet orifice(s) and sensors adjacent to, or near, the blower inlet, therefore the turbulence created at the air inlet by a blockage creates an ‘implied’ flow in and around the sensors. Thus, during times of blockages, the sensors of known systems are incapable of accurately controlling the desired air/fuel mixture, due to the swirling and turbulent implied flows washing over the sensors.
Known systems are therefore unable to accurately control the air/fuel mixture during times when the air inlet, or flue, is partially or completely blocked.
With the foregoing problems and concerns in mind, it is the general object of the present invention to provide a fuel equalization system that can accurately detect and respond to situations of air blockage so as to maintain safe air/fuel mixtures.